Filter condition indicator

ABSTRACT

A pressure-responsive filter indicator assembly in a domestic clothes drier responsive to changes in a pressure drop across the filter positioned in an air exhaust passage to provide a continuously visible signal that is terminated only by manual reset operation. The indicator assembly includes a lighttransmitting member and a diaphragm movable between two positions, with the light-transmitting member providing a visible signal on the control console of the drier when the diaphragm is in one position. The diaphragm is responsive to changes in the pressure drop across the filter to move to the position in which the light-transmitting rod provides a visible signal on the console.

United States Patent Mason 1 Feb. 8, 1972 [54] FILTER CONDITION INDICATOR 211 App]. No.: 39,455

Cobb et al. ..34/l33 Primary Examiner-Frederick L. Matteson Assistant Examiner-Harry B. Ramey Attorney-James S. Nettleton, Thomas E. Turcotte, Burton H. Baker, Donald W. Thomas, Gene A. Heth, Franklin C. l-larter, Anthony Niewyk, Robert J. Judd and Hill, Sherman, Meroni, Gross & Simpson ABSTRACT A pressure-responsive filter indicator assembly in a domestic clothes drier responsive to changes in a pressure drop across the filter positioned in an air exhaust passage to provide a continuously visible signal that is terminated only by manual reset operation. The indicator assembly includes a light-transmitting member and a diaphragm movable between two positions, with the light-transmitting member providing a visible signal on the control console of the drier when the diaphragm is in one position. The diaphragm is responsive to changes in the pressure drop across the filter to move to the position in which the light-transmitting rod provides a visible signal on the console.

10 Claims, 5 Drawing Figures msmanm smz SHKET 2 BF 2 ANTHONY MAS 01v 1 FILTER CONDITION INDICATOR BACKGROUND OF THE INVENTION l. Field of the Invention The present invention relates to drying apparatus and more particularly to a domestic clothes drier having a particle filter.

2. Description of the Prior Art Pressure-responsive indicator assemblies are known for indicating gas pressures or indicating filter conditions in air intake systems of vacuum cleaners or internal combustion engines. One particular type of device utilizes generally concentric cylindrical members of ditferent colors, the outer of which is movable against a spring by a pressure activated magnetic means so that at low pressures the magnetic means is moved away and the spring snaps the outer member into a visible position and blocks view of the inner member. This operation is automatically reversed at high pressures. Another type of device utilizes a diaphragm stable in two positions with an upstanding cup member attached to an upper surface of the diaphragm. The diaphragm moves in accordance with the pressure so that at normal pressures the cup member covers a signal indicator and at low pressures the cup member exposes the signal indicator. A manual actuator moves the diaphragm back to normal position after the filter has been cleaned. These types of pressure-responsive indicators have multiple parts that are relatively complex to manufacture, and are generally not suitable for use in fabric-drying apparatus.

SUMMARY OF THE INVENTION The invention provides a simple mechanically actuated indicator for producing a signal in response to changes in a predetermined pressure drop across a particle filter of a fabric dryer. A housing with an interior chamber has a diaphragm adapted to be stable in two positions secured to the housing to partition the interior of the housing into two separate chamber portions. Fluid-communicating means are provided for each of the chamber portions so that opposite sides of the diaphragm are exposed to pressure at opposite sides of the filter. The housing also carries a light-transmitting rod member movable within one of the chambers for repositioning of the diaphragm to its normal position. The diaphragm has a colored surface facing the rod member and in registry therewith so that when the colored surface and the rod are brought adjacent to each other, the color is visible at the other end of the rod, which end is positioned for viewing. During operation, the outer indicator face appears dark when the filter is unclogged. As it clogs, the pressure drop across the filter increases and the diaphragm moves toward the rod member so that the colored surface of the diaphragm is visible at the outer rod face. After unclogging, the rod is axially manually moved against the diaphragm to reposition the diaphragm for normal operation.

DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the invention and its organization, construction and operation will be best understood by reference to the following detailed description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings, in which:

FIG. I is a front elevational view of an exemplary embodiment of a clothes dryer incorporating the principles of the present invention;

FIG. 2 is a side elevational view of the clothes dryer of FIG. I, with a portion of a side panel cut away to show the relative disposition of certain parts;

FIG. 3 is a diagrammatic view of a portion of the clothes dryer of FIG. 1 showing an embodiment of the indicator assembly disposed therein and constructed in accordance with the principles of the present invention;

FIG. 4 is a partial diagrammatic view of the indicator assembly of FIG. 3 in an activated position; and

FIG. 5 is a diagrammatic view of another embodiment of the indicator assembly constructed in accordance with he principles of the invention.

DETAILED DESCRIPTION OF THE INVENTION In FIG. I of the drawings, an embodiment of a drier appliance 10 is illustrated generally as comprising a cabinet 11 having a control console lla carried thereon and housing a control device, such as a selectively presettable timer 13.

The appliance 10 includes means forming a treatment zone in which is mounted a rotatable tumbling drum 12. An access door 13 is provided on the front of the appliance so that fabrics can be placed in and removed from the interior of the drum 12 for exposure to currents of temperature conditioned air.

In the rear of the cabinet 11, an air inlet 14 is provided and interconnected with a heater duct assembly 15 in a manner to provide heated air to the interior of the drum 12 during a drying operation of the appliance. An exhaust opening 16 is provided in spaced relation from the air inlet 14 and is interconnected to an exhaust duct assembly 17.

A separating means comprising a lint or particle filter 18 is positioned between the exhaust duct assembly 17 and the exhaust opening 16 so as to entrap any and all particles carried by the exhaust airstream before it is released to ambient atmosphere. A fan assembly 19 forms a fluid translation means for driving a supply of fluid through a circuit which includes the treatment zone in the form of a stream, thereby to entrain lint and other impurities from the materials in the treatment zone. Thus the fan assembly circulates air within the appliance and drives a lint-laden airstream through the exhaust passage 20. A drive motor 21 is provided with a shaft 21a at one side thereof to drive the fan assembly 19 and with a pulley 21b at the opposite side with an associated drive belt 22 arranged to drive the drum 12. A plurality of support wheels 24 and 25 are positioned within the cabinet in operative relation to the drum 13 so as to maintain the rear portion of the drum 13 adjacent a bulkhead 27. For additional details of such appliance constructions and means of operation, attention is directed to Miller et al. US Pat. No. 3,398,465 and to Cobb et al. US. Pat. No. 3,409,997 owned by the assignee of the present invention.

In accordance with this invention, a filter condition indicator assembly 30 is provided to provide a visible signal at the control console 11a.

The indicator assembly 30 is provided with a housing 33 comprising a first or lower somewhat cup-shaped housing member 34 and a mating second or upper housing member 35 held in position by spring clip means 330 and together defining an interior chamber 36. The lower housing member 34 is provided with a nipple 32a connected to a tube 32 which has its opposite end connected to the downstream of backside of the filter 18. Thus, tube 32 communicating the pressure of the exhaust air on the downstream side of the filter 18 to the nipple 32a and thereby to the interior chamber 36. A nipple 31a is connected with a tube 31, which has its other end connected to the upstream of oncoming side of the filter 18. In this manner, the pressure of exhaust air on the upstream side of the filter 18 is communicated to the nipple 31a and thereby to the interior of the housing 33. This arrangement is diagrammatically indicated at FIG. 3. The filter 18 is provided with a handle 18a facilitating its removal from the filter housing for cleaning and the like.

Referring further to the housing 33, it will be noted that the lower housing member 34 is also provided with a central opening 34a forming a bearing support surface to accommodate positioning and axial movement of a rodlike indicator member 40. The indicator member 40 is a substantially rod-shaped elongated cylinder and is preferably composed of a translucent or light-transmitting material, such as an acrylic resin. One end face 40a is provided with a conically recessed surface which is highly polished thereby to form a substantially totally reflective surface. The opposite end of the indicator member 40 protrudes through the opening 34a of the housing member 34 and has formed therein a signal surface which is visible through the control console 11a. The indicator member 40 is provided with a retaining means in the form of an O-ring 41a interior the chamber 36 in contact with the peripheral wall edges of the opening 34a and thereby insuring that indicator member 40 cannot be withdrawn from the housing 33. A continuous biasing means takes the form of a coil spring 41b and is biased between the exterior wall portions of orifice 34a and a clip member 410, anchored to the member 40. It will be noted that this manner of securement allows the indicator member 40 to move slidably through the opening 34a and in an axial direction interiorly of the chamber 36 when mechanical pressure is applied to the face 40b against the bias of the coil spring 41b.

in order to provide a signal responsive to a pressure differential across filter 18, a flexible fluid-impervious diaphragm member 37 is suitably secured and clamped between the upper and lower housing portions 35 and 34 which partitions the interior of the chamber 36 into an upper portion 36a and a lower portion 36b. The diaphragm 37 is adapted to assume two stable positions, such as shown in FIGS. 3 and 4 and completely separates the chamber portions 36a and 36b from each other so that no fluid communication exists therebetween and two separate pressure chambers are provided.

A generally cup-shaped upstanding wall portion or enclosure member 38 is provided along one side of the diaphragm member 37 in registry with rod end 40a. The opening of the cup-shaped enclosure member 38 has a somewhat larger diameter than the diameter of the indicator member 40 so that the indicator member 40 easily fits within the cup-shaped enclosure member 38. The interior surfaces of the cup-shaped enclosure member 38 are colored, such as with a coating of a luminescent or fluorescent paint as shown at 38a. Other color bases can also be provided if desired, for example, a metallic coating could be used which surface could be suitably polished. As will be appreciated, the enclosure member may be formed integrally with the diaphragm member as shown but a separate member could be provided as a matter of choice.

In operation, lint-laden exhaust air is drawn into the exhaust opening [6 by fan assembly 19 at a predetermined pressure and carries any lint or other particulate material from the fabric being dried through the exhaust duct assembly and into contact with the filter member 18. The pressure at the upstream side of the filter is communicated to tube 31 and into the indicator assembly 30 at chamber portion 36a so as to provide a pressure on one side of the diaphragm assembly 37. The lint-free exhaust air passes through the filter 18 after separation in the filter, leaving any particles therein on the filter, and the lint-free air passes into ambient atmosphere via the exhaust opening 20.

A pressure drop occurs across the filter and the pressure at the downstream side of the filter is communicated through the tube 32 into the indicator assembly 30 at the chamber portion 36b. When the filter is clean, the pressure at the upstream and downstream sides of the filter will be substantially equal and the diaphragm assembly 37 will remain in the position shown at FIG. 3. As drying operations continue and particles clog the filter 18, the pressure upstream of the filter will become greater than the downstream pressure thereof, due to an increasing pressure drop across the filter and when a predetermined increase in the pressure drop occurs indicating a clogging of the filter, the diaphragm assembly will be moved toward the interior of the housing 33 and into the changed position shown in FIG. 4. At the position of FIG. 4, the cupshaped enclosure member 38 of the diaphragm assembly 37 is adjacent and confronts the face 40a of member 40. Inasmuch as the interior surfaces 38a are colored, the color thereof is transmitted through the member 40 and is visible as a glowing colored signal at the face 40b on the control console.

The color of surface 38a is visible at face 40b of member 40 when the diaphragm positions enclosure member 38 adjacent and confronting face 40a because light falling on face 40b is transmitted along member 40 until it strikes face 400, which is polished so as to be substantially totally reflecting. Light striking face 40a is reflected in a direction substantially normal to the axis of member 40 so that the reflected light passes out through the sidewall of member 40. When enclosure member 38 is adjacent the end of member 40, as shown in FIG. 4, the transmitted light falls on colored surface 38a. Colored surface 38a reflects a portion of the light falling thereupon dependent on the nature and color of the surface. For example, a surface which appears to be red reflects light in the red portion of the visible spectrum. Accordingly the reflected colored light will strike face 400 and be reflected toward face 4012 thereby making face 40b appear to be the same color as surface 38a. When the diaphragm is in the position shown in FIG. 3, light leaving member 40 after being reflected by surface 40a will strike no surface adjacent member 40, and thus will not be reflected back into member 40. Accordingly, no light will be reflected from face 40a toward face 40!) and face 40b will appear dark.

In this manner, the operator is continuously appraised of the condition of the filter. Upon appearance of the glow signal, the operator is advised that the filter is clogged and should be cleaned. Since the diaphragm assembly is stable in the position of FIG. 4 as well as in the position of FIG. 3, the indicator will continuously provide a visible signal until the diaphragm assembly has been manually reset to its nonindicating position by the operator. Thus, if the filter is not cleaned at the end of a particular drying cycle, the operator will be reminded to clean the filter before beginning another drying cycle. After the filter has been cleaned and replaced, the operator merely applies light pressure to the face 40b of member 40 to move it axially inwardly and thereby mechanically move the diaphragm assembly to its reset position and condition the apparatus for further operation.

Another embodiment 30 of the indicator assembly of the invention is shown at FIG. 5 and like parts are identified by the same reference numerals with a prime suffix. Thus, the housing 33 is formed of a lower member 34' and a mating upper member 33' and has an interior chamber 36, which is divided by a diaphragm assembly 37' and into two chamber portions 36a and 36b respectively. The chamber portions 36a and 36b are adaptable to be in fluid communication with the upstream and downstream side of a filter respectively via nipples 31a and 32a. The housing member 33 is provided with a spacing means 33a in the form of a depressed groove or the like extending into the chamber 36' so as to space the diaphragm assembly 3'7 a distance from member 33'. The diaphragm assembly is provided with an upstanding enclosure or sleevelike member 38' having the interior surfaces 380' thereof colored as by coating with a luminescent, fluorescent or other colored material.

A spaced bracket member 51 is provided which is made of a magnetizable material, such as soft steel. A permanent magnet latch member 52 is anchored to an interior wall of the housing member 34' in registry with bracket member 51 so that when the diaphragm assembly 37' moves into the vicinity of the latch member 52, the bracket member 51 will become magnetically anchored to the latch member 52 and thus maintain the diaphragm in first operative position. A spring member 53 is positioned between the diaphragm assembly 37 and the housing member 34' so as to bias the diaphragm assembly 37' away from the light-transmitting rodlike member 40' and thereby maintain the diaphragm assembly in a second position.

The operation of this embodiment is essentially similar to that previously described and a predetermined pressure differential caused by clogging of the filter member causes the diaphragm assembly to move toward the member 40' and compress the spring member 53. The colored sleevelike member 38 is thus moved to enclose at least face 40a of the member 40' and a visual signal appears at the face 40b. The diaphragm assembly 37' is held inoperative position by the magnetic force between latch member 52 and bracket member 51 even when the drying apparatus is shut off and no pressure differential exists. Of course, after the filter has been cleaned, the diaphragm assembly simply is reset by application of light pressure on the member 40' to overcome the magnetic bias.

Many changes and modification of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention and it is to be understood that I wish to include within the patent warranted hereon all such changes and modifications as may be reasonably and properly included within the scope of the appendant claims.

The embodiment of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a laundry appliance,

means forming a treatment zone in which materials are to be treated,

translation means forming a circuit including said treatment zone and by means of which a supply of conditioning fluid is directed in the form of a stream through said treatment zone to entrain lint and other impurities from the materials being treated,

a separating means in said circuit downstream of said treatment zone through which all of the fluid in said circuit is directed to filter the stream,

an elongated translucent light-transmitting member having a substantially totally reflecting end slidably supported for movement into a chamber,

actuating means in said chamber, movable between first and second position responsive to changes in the pressure drop across said separating means whenever the separating means becomes clogged,

and means providing a colored surface adjacent said reflecting end of said elongated light-transmitting member when said actuating means is in one of said first and second positions,

thereby to form a visible colored signal at the other end of said light-transmitting member, and biasing means acting on said actuating means to retain it in a stable position after actuation, but yieldable under sliding movement of said light-transmitting member to accommodate resetting by the operator.

2. A fabric-drying apparatus including a tumbling drum with inlet and exhaust openings in communication with the interior thereof,

an exhaust passage leading from said exhaust opening,

means to cause a flow of drying fluid through said apparatus,

a filter associated with said exhaust passage to intercept particulate material carried by said fluid in said passage, an indicator connected to said passage on opposite sides of said filter adapted to produce a signal in response to a predetermined pressure drop across said filter, wherein said indicator includes a diaphragm carried in a housing with opposite sides of said diaphragm exposed to the fluid pressure on opposite sides of said filter,

a translucent rod having one end substantially totally reflecting carried by said housing and arranged for motion into said housing in opposition to a biasing force,

an upstanding member carried by said diaphragm provided with a fluorescent surface positioned so as to confront said reflecting end when said diaphragm is in one position,

means to releasably retain said diaphragm in said one position and wherein said diaphragm is movable to a second position in response to movement of said rod into said housing.

3. In a fabric-drying apparatus having a cabinet, a rotatable tumbling drum within said cabinet, means circulating air through said drum, air inlet and air exhaust openings in communication with said drum, an exhaust passage in communication with said exhaust opening for directing air therefrom, a filter member operatively associated with said exhaust opening for interception and entrapment of any particulate material carried by said air within said exhaust passage, the improvement comprising:

an indicator assembly mounted on said cabinet and including a housing having an interior chamber,

a flexible diaphragm member adapted to be stable in two positions and being positioned within said housing so as to divide said chamber into two pressure com a rtments, said housing having means for providing UlCl communication with opposite sides of said filter device arranged so that each pressure chamber is in fluid communication with a respective opposite side of said filter device,

a light-transmitting rodlike member mounted on said housing for axial movement into one of said pressure compartments, said rodlike member having opposed end faces,

one such end face being visible outside said cabinet and the other end face being substantially totally reflecting and positioned in the interior of said pressure compartment, and

a wall member having a colored surface positioned in registry with said other end face so as to confront a portion of said rodlike member,

said wall member being attached to said diaphragm member for movement therewith in response to changes in a pressure differential between said pressure compartments from a first position remote from said rodlike member to a second position adjacent said rodlike member with said colored surface facing said reflecting end face so that the colored surface of the wall member is visible at said one end face.

4. In a fabric-drying apparatus as defined in claim 3 wherein said reflecting end faCe interior of said housing is a conically recessed highly polished surface, and said wall member is a circular enclosure adapted to receive said reflecting end face.

5. in a fabric-drying apparatus as defined in claim 3 wherein a biasing means is associated with said rodlike member urging said member away from said diaphragm member.

6. In a fabric-drying apparatus as defined in claim 3 wherein a means is associated with said diaphragm member for releasably retaining said diaphragm member in said second position.

7. In a fabric-drying apparatus as defined in claim 3 wherein a biasing means is positioned between said diaphragm member and said rodlike member for urging said diaphragm member toward said first position.

8. In a fabric-drying apparatus as defined in claim 7 wherein said biasing means comprises a magnetizable member radially spaced from said enclosure member and said housing is provided with a permanent magnet member mounted within said interior chamber in registry with said magnetizable member for releasably maintaining the diaphragm member in said second position.

9. In a fabric-drying apparatus as defined in claim 3 wherein said rodlike member is composed of an acrylic resin material and said wall member is circular enclosure coated at its interior surfaces with a fluorescent material.

10. The method of operating a laundry appliance which includes the steps of directing a supply of conditioning fluid in the form of a stream through a circuit including a treatment zone wherein the stream entrains lint and other impurities from the materials being treated,

at one point in the circuit downstream of the treatment zone directing the stream through a separating means to filter the stream,

positioning a diaphragm at a first position in response to pressure on one side of said separating means, positioning said diaphragm at a second position in response to pressure on the other side of said separating means, changing the diaphragm between said first and second positions in response to changes in the pressure drop across said separating means when clogging occurs, and providing a visible signal at one end surface of a light-transmitting rod having another end surface which is substantially totally reflecting when said diaphragm is positioned in one of said positions adjacent said reflecting end surface, thereby to indicate the clogged condition of the separating means. 

1. In a laundry appliance, means forming a treatment zone in which materials are to be treated, translation means forming a circuit including said treatment zone and by means of which a supply of conditioning fluid is directed in the form of a stream through said treatment zone to entrain lint and other impurities from the materials being treated, a separating means in said circuit downstream of said treatment zone through which all of the fluid in said circuit is directed to filter the stream, an elongated translucent light-transmitting member having a substantially totally reflecting end slidably supported for movement into a chamber, actuating means in said chamber, movable between first and second positions responsive to changes in the pressure drop across said separatiNg means whenever the separating means becomes clogged, and means providing a colored surface adjacent said reflecting end of said elongated light-transmitting member when said actuating means is in one of said first and second positions, thereby to form a visible colored signal at the other end of said light-transmitting member, and biasing means acting on said actuating means to retain it in a stable position after actuation, but yieldable under sliding movement of said lighttransmitting member to accommodate resetting by the operator.
 2. A fabric-drying apparatus including a tumbling drum with inlet and exhaust openings in communication with the interior thereof, an exhaust passage leading from said exhaust opening, means to cause a flow of drying fluid through said apparatus, a filter associated with said exhaust passage to intercept particulate material carried by said fluid in said passage, an indicator connected to said passage on opposite sides of said filter adpated to produce a signal in response to a predetermined pressure drop across said filter, wherein said indicator includes a diaphragm carried in a housing with opposite sides of said diaphragm exposed to the fluid pressure on opposite sides of said filter, a translucent rod having one end substantially totally reflecting carried by said housing and arranged for motion into said housing in opposition to a biasing force, an upstanding member carried by said diaphragm provided with a fluorescent surface positioned so as to confront said reflecting end when said diaphragm is in one position, means to releasably retain said diaphragm in said one position and wherein said diaphragm is movable to a second position in response to movement of said rod into said housing.
 3. In a fabric-drying apparatus having a cabinet, a rotatable tumbling drum within said cabinet, means circulating air through said drum, air inlet and air exhaust openings in communication with said drum, an exhaust passage in communication with said exhaust opening for directing air therefrom, a filter member operatively associated with said exhaust opening for interception and entrapment of any particulate material carried by said air within said exhaust passage, the improvement comprising: an indicator assembly mounted on said cabinet and including a housing having an interior chamber, a flexible diaphragm member adapted to be stable in two positions and being positioned within said housing so as to divide said chamber into two pressure compartments, said housing having means for providing fluid communication with opposite sides of said filter device arranged so that each pressure chamber is in fluid communication with a respective opposite side of said filter device, a light-transmitting rodlike member mounted on said housing for axial movement into one of said pressure compartments, said rodlike member having opposed end faces, one such end face being visible outside said cabinet and the other end face being substantially totally reflecting and positioned in the interior of said pressure compartment, and a wall member having a colored surface positioned in registry with said other end face so as to confront a portion of said rodlike member, said wall member being attached to said diaphragm member for movement therewith in response to changes in a pressure differential between said pressure compartments from a first position remote from said rodlike member to a second position adjacent said rodlike member with said colored surface facing said reflecting end face so that the colored surface of the wall member is visible at said one end face.
 4. In a fabric-drying apparatus as defined in claim 3 wherein said reflecting end faCe interior of said housing is a conically recessed highly polished surface, and said wall member is a circular enclosure adapted to receive said reflecting end face.
 5. In a fabric-drying apparatus as defined in claim 3 wherein a biasIng means is associated with said rodlike member urging said member away from said diaphragm member.
 6. In a fabric-drying apparatus as defined in claim 3 wherein a means is associated with said diaphragm member for releasably retaining said diaphragm member in said second position.
 7. In a fabric-drying apparatus as defined in claim 3 wherein a biasing means is positioned between said diaphragm member and said rodlike member for urging said diaphragm member toward said first position.
 8. In a fabric-drying apparatus as defined in claim 7 wherein said biasing means comprises a magnetizable member radially spaced from said enclosure member and said housing is provided with a permanent magnet member mounted within said interior chamber in registry with said magnetizable member for releasably maintaining the diaphragm member in said second position.
 9. In a fabric-drying apparatus as defined in claim 3 wherein said rodlike member is composed of an acrylic resin material and said wall member is circular enclosure coated at its interior surfaces with a fluorescent material.
 10. The method of operating a laundry appliance which includes the steps of directing a supply of conditioning fluid in the form of a stream through a circuit including a treatment zone wherein the stream entrains lint and other impurities from the materials being treated, at one point in the circuit downstream of the treatment zone directing the stream through a separating means to filter the stream, positioning a diaphragm at a first position in response to pressure on one side of said separating means, positioning said diaphragm at a second position in response to pressure on the other side of said separating means, changing the diaphragm between said first and second positions in response to changes in the pressure drop across said separating means when clogging occurs, and providing a visible signal at one end surface of a light-transmitting rod having another end surface which is substantially totally reflecting when said diaphragm is positioned in one of said positions adjacent said reflecting end surface, thereby to indicate the clogged condition of the separating means. 